A method, for generating a pulse sequence as well as a device for its execution, is known from EP 0 287 661 A1. According to this publication, for example, the parameters: pulse shape, amplitude, and duration as well as the temporal order of the pulses of the sequence are entered via the input keyboard of the computer, and thereby the complete sequence is programmed.
Even though the generation of the pulse sequence is in principle simple, it appears to be, however, disadvantageous in the known method that the input of the numerous parameters is complicated for the user because it is time-consuming.
The known process would still be afflicted with this disadvantage even if, instead of a customary input keyboard, an arrangement further known from EP 0 026 833 A2 should be used for the data input, offering to the user a supply of parameters to be entered in the form of scales allocated to these individually on a screen, on which scales, by shifting, e.g. mouse-controlled, of an arrow representation or rotation of a pointer representation, he can mark an input parameter value and/or limit its range. The time expenditure required for a process modified in such a manner for a complete data input would correspond, however, at least to that which must be accepted by using the method known per se from EP 0287661 A1.
It is also known practice to define pulse sequences graphically by means of a so-called light pen. This, too, although it appears to be "more graphic" and thus simpler than an input of digital abstract values, is complicated and time-consuming inasmuch as, because of the strongly differing pulse durations of the control signals in the plotting of such a sequence, the time scale of the "drawing" has to be changed very frequently.
A method of the type mentioned at the outset is finally known from IEEE Transactions on Biomedical Engineering, vol. BME-34, No. 12, December 1987; D. Foxvog et al.: "PUPA: A pulse programming assistant for NMR imaging", pages 938-942. Here, after the selection and possible modification of a pulse or of a pulse sequence, which is possible only by means of the input keyboard of the computer, the pulses or the pulse sequence are displayed on a screen, so that further required modification is facilitated with the aid of the graphic representation.